By Dr. Terry Simpson
Most people hear the name Urolithin A and think it belongs in a commercial about prostate health. It sounds like something a man named “Gary, 62,” would talk about while fishing. But Urolithin A has nothing to do with plumbing. Instead, it sits at the center of a new wave of longevity science focused on how our cells clean up old, broken parts.
As we age, our mitochondria—the tiny power centers inside our cells—start to slow down. They build up damage and stop working well. Eventually, this pile-up makes us lose strength and energy. That’s where Urolithin A comes in. It helps switch back on a process called mitophagy, which is basically the cell’s recycling program for old mitochondria.
You cannot eat Urolithin A directly. Instead, your body makes it when your gut bacteria break down special plant compounds called ellagitannins. These are found in foods like:
Green tea is usually known for its catechins, but it also contains ellagitannins like strictinin. After you drink it, your gut bacteria break these tannins apart and create ellagic acid, which can later turn into Urolithin A.
However, this only works if you have the right microbes. And here’s the surprising part:
Most people do not.
Studies show that only 12% to 40% of adults naturally produce Urolithin A from food. Everyone else makes little to none because their gut bacteria simply aren’t built for the job.
Your microbiome—the community of bacteria living in your digestive system—decides whether you make Urolithin A or not.
People who produce Urolithin A usually have:
People who don’t produce it (called “metabotype zero”) lack those bacteria or the gene pathways needed. Eating more pomegranates or drinking more green tea does not fix this. No diet, including keto or Mediterranean, has been shown to turn a non-producer into a producer.
This is why two people can eat the same food, and only one makes Urolithin A.
In older adults, researchers have tested Urolithin A supplements for up to 4 months. These studies show several encouraging results:
Even so, there are limits. Trials show no meaningful improvement in:
So the biology looks better, but major clinical outcomes have not changed.
Scientists also study Urolithin A in senescent cells—cells that have stopped dividing but still cause inflammation. In the lab, Urolithin A can:
All of this sounds exciting. However, these findings are from cell culture, not humans. They give us clues, not guarantees.
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